Adjustable internal expansion grinder



P 7, 1948- s. R. KELLER ADJUSTABLE INTERNAL EXPANSION GRINDER 2 Sheets-Sheet 1 Filed Jan. 29, 1946 INVENTOR Spenaerfi Keller AITDRNEYB Sept. 7, 1 948. s, KELLER 2,448,600

- I ADJUSTABLE INTERNAL EXPANSION GRINDER Filed Jan. 29, 1946 2 Sheets-Sheet 2 INVENTOR.

d am'er/f/fd/er myrmwea ATI'DRNEYB Patented Sept. 7, 1948 UNITED STATES PATENT OFFICE ADJUSTABLE INTERNAL EXPANSION GRINDER Spencer R. Keller, Handley, W. Va.

Application January 29, 1946, Serial No. 644,006

This invention relates to improvements in internal grinding tools which may be used with lathes, milling machines, drill presses and portable drills and other power driven apparatus for truing cylinder walls and similar article's having circularinteriorbores therein. v

In accomplishing the various advantages and objects for which the invention is characterized, an adjustable grinder is provided which is designed to be operated at low or high speeds depending upon the-type of work being performed.

An object of the invention is to provide a grinder having a perfect circle formation in crosssect'ionwhichmay be adjusted to increase or decrease-the outside dimensions thereof.

It is adapted to grindthe internal bores of articles to a perfect circle with or without the use of lubricant.

Another object of'the invention is to provide a ,tool that is quickly and accurately adjusted, worn or broken grinding surfaces being easily replaced and on the whole the tool is simple, duraable, and can be manufactured at a low cost.

The tool can be quickly dismantled and reassembled, the action of grinding being similar to I that of a solid grinding wheel, and will operate efliciently in grinding small or large diameter surfaces.

With the above and other objects and advantages in view the invention consists of the novel details of construction, arrangement and combination of parts more fully hereinafter described, claimed and illustrated in the accompanying drawings in which:

Figure 1 is an elevational view of an embodiment of the invention partly in section.

Figure 2 is a sectional view on the lin 2-2 of Figure 1.

Figure 3 is a sectional view on the line 3-3 of Figure 1.

Figure 4 is a sectional view on the line 4--4 of Figure 1.

Figure 5 is a perspective view of the shoes.

Figure 6 is a perspective view of the shims used in conjunction therewith.

Figure '7 is a perspective view of the grinding elements.

Figure 8 is an elevational view partly in section of a modification of the invention.

Figure 9 is a sectional view on the line 9-9 of Figure 8, and

Figure 10 is an end view of Figure 8.

Referring more in detail to the drawings the reference numeral designates the shaft or spindle that is adapted to be the power mecha- 5 Claims. (Cl. 51-4843) nism which is used for the g ind n J' e performed and as stated it could be a lathe, drill press, milling machine, portable drill or similar mechanism.

The shaft 20 is provided with a reduced end portion 22, forming a shoulder 24 which forms an abutment for the removable collar 26. A pin 28 anchored in the collar 26 is received in the shaft 20 for preventing rotation of the same relative to the collar 26.

Positioned in face to face relation with the collar 26- are the segmental grinding stones or surfaces 30 which are provided with keys 32, see Figure 7, adapted to be received in keyways 34 in the collar 26. These keyways 34 are diametrically positioned in the collar 26 and act as guides in positioning the stones 30 and also prevent angular displacement thereof.

The outer periphery of the stones 30 are notched or scalloped at 36 to provide means for effectively disposing of the particles removed from the articles being ground and the particles collecting therein form with the lubricant being used a grinding compound which further aids in grinding of the articles.

The stones an are separated by complementary shaped shoes 38 having semicircular portions 43 which conform with the reduced end 22 of the shaft 20 and the recesses 42, see Figure '7, in the stones 30. The straight wing portions 44 of the shoes 38 contact the flat surfaces 46, see Figure Z, of the stones 30 and the inner faces of the wings 4'4 are provided with complementary cone-shaped seats 48. The flat surfaces 46 of the stones 3E3 may also be provided with complementary conical seats 50.

Positioned on the shaft 20 in face to face relation with the stones 30 is a second collar 52 which bears against the stones and with the aid of a nut 54 on the threaded end 56 of the shaft 20, the stones 30 are clamped between the collars 2B and 52. The collar 52 is provided with a circular depression 58, see Figure 4, to thus provide a circular bearing surface 60 for the purpose of binding the stones 30 in a firm manner.

Threadably mounted in the collar 26 in diametrically opposed relation to each other are adjusting screws 62, each having a socketed end 64 for receiving a wrench for adjustment and a cone-shaped end 66 which is received in the seats 48 of the shoes 38 resting within the seats 50 of the stones 3!) as previously described.

The screws 62 and their ends 66 are so shaped that the shoes 38 may be adjusted to enlarge the outer diameter of the stones 30 in thousandths of an inch. Graduations 68 on the collar 26 are arranged about the screws 62 to assist in permitting such fine adjustment.

The stones 38 can be adjusted outwardly for wear and also to fit larger internal bores. Thus, the stones 30 can be adjusted to fit various sized bore diameters.

The shims shown in Figure 6 having the conical seats I2 may be used when the periphery of the stones 38 are worn or when necessary to increase the diameter of the grinding surfaces beyond the ability of adjustment by the shoes 38.

In Figures 8, 9 and 10 there is shown a modified form of the invention which is used for smaller work than the grinder previously described.

In the modified form of the invention the shaft 74 is provided with an integral collar 16 and a threaded end 18 on which the sleeve 80 is threadably mounted for adjustment thereon. The sleeve 80 is provided with a forward bore 82 to receive the bolt 84 which retains the collar 86 and grinding stones 88 against the sleeve 80.

The collar 86 has a depression 98 similar to the depression 58 in the collar 52 and provides the bearing surfaces 92. The stones 88 are provided with keys 84 adapted to be received in the keyways 95 formed in the forward end of the sleeve 88. The stones 88 are separated by shoes 98 similar in formation to shoes 38 having semi-circular portions I88, wings I02 and seats I04. The collar 88 is provided with adjusting screws I86 having sockets I88 in the end thereof, similar to screws 62.

In this structure if the surface being ground has a tendency to break the bolt 84, a new one can be inserted and it will be cheaper than replacing an entire new shaft.

.t is believed that the operation and adjustment of the tool will be apparent to those skilled in the art and it is to be understood that changes in the details of construction, arrangement and combination of parts may be resorted to without departing from the spirit of the invention orthe scope of the appended claims."

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. A device of the character described, comprising a shaft, a shoulder formed on said shaft, a collar on said shaft abutting said-shoulder, a second collar on said shaft segmental grinding elements interposed between said collars, means on said shaft for fixedly retaining said grinding elements between said collars, complementary shaped expanding means positioned intermediately of said grinding elements and means in said first mentioned collar for acting on said expanding means intermediate said elements for adjusting the diameter of said elements.

2. The invention as in claim 1 wherein said shaft is sectional and the means for retaining said elements on said shaft comprises a removable bolt.

3. The invention as in claim 1 wherein said adjusting means are provided with conical shaped ends and the means interposed between said elements is provided with conical seats to receive the conical shaped ends of said adjusting means.

4. The invention as in claim 1 wherein means are provided to coact with said adjusting means whereby the diameter of the elements may be increased beyond the capacity of the adjusting means.

5. In an adjustable abrading tool comprising a shaft, a collar anchored to said shaft, said collar being provided with a plurality of radially disposed keyways, a plurality of shoe means surrounding said shaft,- a plurality of segmental grinding stones surrounding said shaft and contacting said shoe means, said stones being provided with radial key portions slidably engaging said collar keyways whereby said stones are held against angular movement relative to the collar but may be moved radially relative to the same, adjusting screw means mounted in said collar for axial movement and engaging said shoe means for separating the same relative to each other whereby axial movement of said screw-means causes radial movement of said shoe means'to expand the peripheral outline formed by said segmental stones and releasable means carried by said shaft for locking said stones against said collar for rotation therewith. I

SPENCER R. KELLER.

REFERENo scI'rEn f The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,170,585 Beard Aug. 22, 1939 

